Top-Sealing Dampers

Improve Efficiency & Save Money With A Top-Sealing Damper

In order to minimize the transfer of conditioned air, your chimney was built with a damper, designed to close off the flue when it’s not being used. In most older chimney systems, that damper is what’s called a throat damper, installed just above the firebox, closing the flue with a metal plate.

These throat dampers can often stand up to years of functional use, but they do have some marked shortcomings. Because the seal is metal to metal, these dampers won’t close off the flue completely, so leakage — and with it, energy waste — is to be expected. The metal used can also be prone to rust and corrosion, especially if moisture enters the system. Additionally, throat dampers can come off of the track they are seated on, or get stuck because of debris or corrosion. While very common, throat dampers certainly aren’t seen as ideal, especially as our industry has advanced, developing better, more energy-efficient options.

These days, chimney professionals — including those at Old Hat Chimney Service — recommend top-sealing dampers. These provide vastly improved protection against water intrusion, increase energy efficiency and can more quickly and efficiently be installed and serviced. Different top-sealing dampers have been shown to diminish heat loss through the chimney (as compared to throat dampers) by as much as 75 to 90 percent.

How Top-Sealing Dampers Are Different

The first difference is probably pretty obvious: Unlike throat dampers, which are installed down near the “throat” of your chimney, top-sealing dampers are installed at the top of the flue. This prevents water, wind and animal intrusion at the very start of the system.

Materials make a big difference too. Top-sealing dampers include a rubber gasket, which completely seals off the flue in a much more thorough way than the metal plate of a throat damper can.